I think parent refers to the infrastructure that is required to (automatically?) sign certificates by an internal CA and managing the distribution of those certificates. I don't think verification is the issue.
This is correct. You have to consider every step from when the device is manufactured to when something goes catastrophically wrong in the field. All the internal documentation and tools so Joe from support can help customers and Bob in manufacturing can provision devices on his own all while maintaining controls around that process so nothing is getting leaked or abused.